Anyway. I'm having a weird problem playing videos with the xvideo output (e.g. mplayer's -vo xv). I observed this in mplayer, mplayer2 and vlc. Weirdly, it started after I upgraded my video card from a Geforce 200 series to 600.. It looks like this: http://i.imgur.com/wHNMR.jpg , with those square patterns in the video. Another weird thing is that it goes away when I have KWin compositing enabled and the video is running in a window. When I switch to fullscreen or disable compositing the tearing immediately appears. It also doesn't happen in vdpau output. I have checked all my configs to see if I have some vsync option disabled but no, it's enabled everywhere I looked. nvidia-settings is set to sync to my current monitor.